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Lan, Z.*; 余語 覚文*; Mirfayzi, S. R.*; 早川 岳人*; 小泉 光生; Wei, T.*; Shi, B.*; 石本 崇*; Golovin, D.*; 森 隆人*; et al.
no journal, ,
High penetration power of neutrons is potentially useful for realizing opaque object analysis in non-destructive way. Large-scale particle accelerators and nuclear reactors are mostly used for development of neutron analyzing method. A Laser-Driven Neutron Source (LDNS) has been proposed as a new approach of neutron generation for non-destructive analysis. Demonstration experiments on neutron resonance measurement ware performed at ILE, Osaka Univ., Japan. The Peta-watt laser LFEX was used to shoot a CD (deuterated plastic) foil target to produce accelerated charged deuterons. Neutrons are generated by nuclear reaction between a cylindrical beryllium and the accelerated deuteron, and then moderated by a high-density polyethylene (HDP). Neutrons of 1
20 eV were observed with a neutron detector at a 1.8 m using neutron resonance diagnosis technology. This report describes the results of the first experimental demonstration.
余語 覚文*; Mirfayzi, S. R.*; 有川 安信*; 安部 勇輝*; 岩本 晃史*; 早川 岳人*; 小泉 光生; Golovin, D.*; 森 隆人*; Lan, Z.*; et al.
no journal, ,
大阪大学のLFEXレーザー施設において、大強度レーザーを用いたパルス中性子源(LDNS)の開発およびそれを利用した応用研究を進めている。レーザーは、パルス巾が1.5psで、最大出力は、1kJ(1.5
10
Wcm
である。開発した中性子源は1cm程度の大きさで、数十マイクロメータに収束したレーザーをターゲットに照射し、それによって生成したMeVもの高速イオン(水素や重水素粒子)を直径5mmのベリリウムに当てて、核反応により中性子を生成するものである。中性子の生成量は、1ショットあたり10
で、この生成量は、入射エネルギーの4乗で増加することが分かった。さらに、生成した中性子を数cmの大きさのモデレータで減速させ、離れた位置に設置した中性子検出器により、中性子発生から検出までの飛行時間を測定するTOF測定を行った。試料を透過させて中性子の減衰を調べる実験を行った結果、核反応の共鳴による減衰の観測に成功した。
Lan, Z.*; 余語 覚文*; Mirfayzi, S. R.*; 小泉 光生; 早川 岳人*; 有川 安信*; 安部 勇輝*; Golovin, D.*; 森 隆人*; Wei, T.*; et al.
no journal, ,
Neutron resonance diagnosis technology has been developed on reactors and accelerators for over ten years. By employing neutron beams with high transmittance, it is possible to analyse elementary composition, internal temperature and shock waves of thick objects in a non-destructive way. We developed a new approach to generate short-pulse epithermal neutron beams using relativistic intensity laser for the neutron resonance spectral diagnosis, which is known as Laser-driven Epithermal Neutron Source (LDENS). The neutron resonance measuring experiment was implemented at ILE, Osaka Univ. with peta-watt laser LFEX. The experimental results in 2020 demonstrated that LDENS is applicable for neutron resonance measurement. In 2021 experiments, we developed the system to record neutron spectrum with higher quality. Multiple resonance peaks of various isotopes with different temperature were clearly measured. The presentation will introduce the experimental results and discussions including characteristic evaluation of LDENS and temperature dependency of neutron resonance peaks.
Lan, Z.*; 余語 覚文*; 早川 岳人*; Wei, T.*; 加美山 隆*; 佐藤 博隆*; 有川 安信*; Mirfayzi, R.*; 小泉 光生; 安部 勇輝*; et al.
no journal, ,
Neutron resonance diagnosis technology has been developed worldwide for over ten years. By employing neutron beams with high transmittance, it is possible to measure the resonance spectral of samples in the neutron beam-line. We developed a new approach to generate short pulse epithermal neutron beams using relativistic intensity laser for the neutron resonance spectral diagnosis, which is known as Laser-Driven Epithermal Neutron Source (LDENS). Benefit from highly focused laser, the LDENS can provide high temporal accuracy with a compact volume of the source. Therefore, the minimal change of neutron resonance peaks caused by Doppler broadening effect of atom temperature could be detected via single pulse of LDENS. In experiment, we measured resonance at 4.28eV of a 0,1mm Ta plate with serial temperature points (300K-600K) and another resonance at 5.18eV of an Ag plate was recorded as a reference of the neutron signal. The experimental data shows the feasibility of isotope-discriminating atomic thermometer using a single shot of LDENS. More results will be reported in the presentation.
Lan, Z.*; 早川 岳人*; Wei, T.*; 加美山 隆*; 佐藤 博隆*; 有川 安信*; Mirfayzi, S. R.*; 小泉 光生; 安部 勇輝*; 森 隆人*; et al.
no journal, ,
As a new approach of neutron generation with the ultra-short pulse duration and high flux, a Laser-Driven Neutron Source (LDNS) has been studied. A demonstration experiment of neutron resonance spectroscopy using a LDNS has been performed using the petawatt laser LFEX at the Institute of Laser Engineering, Osaka University. A CD foil target was used for an high-density plasma generation. Neutrons were produced by the impact of the high energy ions on a boron converter. A high-density polyethylene surrounding the boron converter slowed down neutron energy to epithermal temperature. A single shot neutron resonance experiment was carried out at a neutron beam line of 1.8m. The neutron resonance peak at 4.28 eV of Ta was measured with different temperature.